Auxiliary charge regulating device



A118- 24, l948 J. A. BOLT ETAL 2,447,793

AUXAILIARY CHARGE REGULATING DEVICE Filed May 22! 1947 3 Sheets-Sheet 1 U8- 24, 1943- J. A. BOLT Erm.

AUXILIRY CHARGE REGULATING DEVICE 3 Shee`ts-Sheet 2 Filed Max 22, 1947 UE- 24 1948 J. A. BOLT ETAL Y 25447793 AUXILIARY CHARGE REGULATING DEVICE 3 Sheets-'Sheet 3 Filed May 22', 1.947

N VEN T0125 JAY/J. 51m 7' Patented Aug. 24Jl 1948 UNITEDA STATES PATENT OFFICE AUxrLrsnYfcnAnoE REGULATING DEVICE poration of Delaware Application my 2z, 1941, serial No. 749,116

'7 claim.

This invention relates to an auxiliary charging device for internal combustion engines and other power units to which it may be adapted; it is particularly concerned with so-called water iniection systems or devices by means of which an auxiliary charging component (which may be water, alcohol, water-alcohol mixtures, liquid saturated hydrocarbons and other solutions, or a mixture thereof) is incorporated in the normal fuel-air mixture during the charging operation to modify the action of the charge, as by functioning as a coolant or antidetonant, antitoxic agent or otherwise. For the sake of brevity, however, the auxiliary charging fluid is in some instances referred to simply as water" in the following description.

The present Iapplication constitutes an improvement on, or an alternate type of auxiliary charging device relatively to, that disclosed in the copending application of Frank C. Mock, Serial No. 588,023 led April 12, 1945; it also embodies a fuel-metering and derichment system of the type described and claimed in another copending application of the said Frank C. Mock, Serial No. 745,003 filed April 30, 1947.

The auxiliary charge metering device of application Serial No. 588,023 incorporates a poppet valve which flows water at a substantially constant head to a metering valve arranged to automatically vary the area of a. metering orifice as a function of an engine condition or conditions, for example, charge pressure and temperature, and it also incorporates a derichment valve control valve which, should the Water supply pressure drop below a predetermined value, will close and open the derichment valve. However, there may be conditions arise under wh'ich the derichment control valve of the device of Serial No. 588,023 will not close promptly, and an object of the present invention is to avoid such contingency.

Another object is to provide Ian auxiliary charging device which may be depended upon to meter an auxiliary charging fluid in a predetermined ratio to a primary fuel and which will cut in and out automatically under predetermined charge conditions.

Another object is to generally improve devices of the type specified.

Th'e foregoing and other objects and advantages will become apparent in view of the following description taken in commotion with the drawings, lwherein:

Figure 1 is a schematic view, principally in elevation, of a carburetor of the speed metering type (Cl. 12S-119) 2 i having the water metering device of the present invention operatively associated therewith;

Figure 2 is a sectional view of the bottom portion of Figure 1, showing th'e primary fuel metering valve and derichment valve, and coacting parts; and

Figure 3 is an enlarged sectional view of the water metering unit.

Referring to the drawings and first to Figure 1.

a primary fuel may be metered to an engine |20 by a carburetor of the speed type generally indicated at l0. Since the particular structure ofthe carburetor i0 has no bearing oh the invention, only such parts are shown in detail as directly coact with the auxiliary charge or water meterlng device. pump which receives fuel by way of a conduit it and is driven in synchronism with the engine by means of a suitable drive connection such as the gear 20, the pump driving a centrifugal governor and at the same time supplying fuel under pressure to a chamber in which' the governor is mounted. The governor is operatively connected to a poppet valve disposed in the fuel conduit upstream of a main metering orifice 6l and a supplemental metering orifice 6I, and controlling flow of fuel to said oriilces, the saidvalve having connected thereto a metering head diaphragm which opposes the opening force exerted on the valve by th'e governor; the arrangement being such that the poppet valve regulates the metering head to beproportional to engine speed for a given area of said orifices. 'Ihe areas of the metering orifices B0 and 6I are variable, however, by means of a single metering needle 96 which is provided with a pair of contoured metering sections 91 and 98. The position of the needle Il is varied in relation to ch'anges in manifold pressure modified by exhaust back pressure and accordingly it is slidable in a bushing 99 and is connected to the movable end of a manifold pressure bellows Ill mounted in a housing IBI to which manifold pressure is communicated by way of a conduit |02, see also Figure 1. The manifold pressure bellows III is in turn connected to the movable end of a smaller bellows 10J, responsive to changes in atmospheric pressure and hence exhaust back pressure and which' is anchored to the adjacent end of the housing III and has its interior vented at i to the atmosphere. For an understanding of the construction and operation of the bellows assembly i, l". reference may be had to a copending application of Frank C.Mock, Serial No. 586,223. Briefly however, in operation, the manifold pres- Briefly, it includes a' pressure feed 3 sure bellows responds to changes in manifold pressure while the bellows |03, being vented to atmosphere, responds to changes in atmospheric pressure which is an index of exhaust back pressure. As manifold pressure increases, the bellows or capsule |00 is compressed, thereby retracting needle 60 from the metering orifices 60, 6|. and as manifold pressure decreases, the bellows |00 expands and projects the needle 60 into said orifices, this action being modified by travel of the bellows |03 in relation to changes in atmospheric pressure, while temperature responsive needle 00 controls metering of fuel across the bypass 63, port 9| and passages 02, 92'.

The main metering orifice 60 constitutes a variable restriction between an unmetered fuel chamber C and a metered fuel`chamber B, 4the latter being in communication with the metered fuel line 55. A supplemental or enrichment metering oriilce is indicated at 5|: it is in alignment with the orice 60 and constitutes a like restriction for regulating the flow of fuel from chamber C by way of passages 63, 63' and valve port '54 to chamber 65 and thence through the said orifice 6| to chamber B. Valve port 64 is controlled by a selectively operable derichment and mixture selector valve 56 which is slidable in a bushing 61 and at its lower end is connected `to a diaphragm 66. A spring 69 normally urges the valve 66 toward open position. Another diaphragm 10 is arranged in spaced relation with respect to the diaphragm 60 and in conjunction with the latter defines a chamber 1|.-V A one-way abutting connection is provided between the lower diaphragm 10 and the upper diaphragm 68 by a member 12 which is secured to the bottom or adjacent end of the valve 66 and constitutes a reinforcement for the upper diaphragm. When the lower diaphragm moves upwardly, the central reinforcing plate 13 thereof engages the member 12.

Beneath the lower diaphragm is a pressure chamber 14 to which an operating pressure may be applied to close the valve 68 when an antidetonant is to be metered to the engine, as will be more fully hereinafter described.

For the purpose of selecting an auto-lean or auto-rich fuel-air ratio, fuel under pressure from the carburetor may be conducted .by way of conduit 06 to a chamber 1| between the upper and lower diaphragms 68 and 10 by means of a mixture selector unit or valve assembly which forms no part of the present invention, its specific structure and method of operation being disclosed in the copending application of Frank C. Mock, Serial No. 745,003, hereinbefore identified. That part of the control system shown in Figure 1 includes an-eiectric solenoid valve 15 provided with an electrical connector or plug 82, a circuit wire 82' connecting the live terminal of the plug with the one contact 220 of a manifold pressure switch 230, to be described, the opposite contact 229' of the switch l230 connecting by wire 02" with a contact 03' adapted to be selectively engaged by a manually operable switch 03 located in the pilots compartment or within easy access of an operator and connected in circuit with a battery 84' by wire 84.

The metered fuel in chamber B flows by way of fuel line 55 into a chamber |06 (note Figure'3) and thence into discharge nozzle chamber |01, from which it is discharged through a nozzle .opening |08 into intake conduit |00 posterior to throttles ||0, ||0'. The dischargeopening |08 is controlled by a discharge nozzle which may.

be of any preferred pressure type; as shown in the present instance, it is slidable in a bushing I2 and has its stem connected to a diaphragm ||I backed up by a spring |4 mounted in a housing or cover ||5, the interior of the latter being vented to the air intake conduit upstream of the throttles ||0 by means of passages ||0 and Ill. When the fuel pressure in chamber |00 attains a predetermined value, for example, ten p. s. i., the nozzle is retracted from the opening |00 and fuel is discharged into the air intake conduit |05.

The chamber |06 contains metered fuel only during normal periods of operation, or without water injection, but when water is being injected, this chamber together with the nozzle chamber |01 also serves as a mixing chamber.

The enginediagrammatically illustrated at |20, Figure 1, is of the radial type and provided with a plurality of cylinders |2| to which air under supercharger pressure is directed by way of manifold |22 and manifold pipes |23, an engine driven or rst stage supercharger being indicated at |24. While not shown in the schematic view of Figure 1, the system is adapted for usey with a second or auxiliary stage supercharger located anterior to the throttles ||0, H0'. The intake conduit |09 is shown connected to a throttle body |45 through which the passage ||1 extends and opens out into the main air intake passage upstream of the throttles ||0. A temperature responsive element 34 is adapted for mounting in the intake manifold and acts by way of a fluid conduit 495 and bellows 33 to regulate the temperature needle 90, Figure 3.

Thedevice generally indicated at |25 is an accelerator pump; it is actuated from the throttles ||0, H0' by means of a link |36 and arm or lever |35. The throttles I0, ||0' are mounted on a pair lof shafts |30 and |4|, which are interconnected for synchronous movement by bell crank lever |31, link |39 and arm |40, the bell crank |31 being also connected to the link |35.

The antidetonant or water metering unit is generally indicated at |50; it is shown in elevation in Figure 1 and in schematic or sectional diagram in Figure 3. Referring to the sectionalv view, a main casting or housing |5| is anchored to a boss |52v formed on the section |09 of the intake conduit adjacent the throttle body |45. The casting 5| is formed with a water inlet chamber |53, an unmetered water chamber |54, a metered water chamber |55, and a discharge chamber |56. Water is taken from a suitable' supply such `as a water tank, not shown, and flows by wayof a conduit |51, Figure 1, to and through a strainer |58 into the chamber |53. A pump |59 is mounted in conduit |51; it may'be of conventional construction having an inbuilt by-pass rendered operative when a predetermined delivery pressure is encountered. and it may be operatively connected to a power control device as illustrated and described in the copending application of Stanley B. Smith and Frank C. Mock, Serial No. 533,296, filed April 29, 1944, .and which latter application also embodies certain features in common with the water metering device as herein disclosed. The water pump is shown in Figure 1 as being electrically driven from a suitable source of supply such as the battery 04', which connects with the pump motor by way of wire |60, switch |6|, contact |50' and wires |62, |62', the'switch |6| being under manual or automatic control, as desired.

Controlling flow of fluid between chambers |53 and |54 is a pressure regulating valve |63, Figure autres Doppel: type, said valve being slidable inavalve housing or guide bushing |84 formed with a. port or ports |85and a valve seat |66. A spring |81 normally urges the valve |88 toward seated position, said spring being adjustable by means such as shims |68. The body of the valve |68 is hollow and at its upper end the valve wall is formed with a bleed |69, the latter permitting a restricted by-pass flow of water from chamber |59,

vthence through the hollow valve body and a passage |69' to chamber |54, so that when the valve is closed, the pressures in said chambers will become equalized under certain conditions and for a. purpose to be described.

Overlying chamber |54 is a diaphragm |18; it

has its peripheral edge clamped between a cap or cover |1| and the adjacent surface of the main casting |5|, and its central portion is engaged between a pair of clamp members on a guide rod |12 whose upper end projects into a. guide pocket or recess formed by the cap |1| and whose lower end carries a ball head |12' in contact with the stem of valve |63. A spring |12 encircles the guide rod |12 and normally urges the latter in a valve opening direction, or downwardly, as shown in Figure 3. The cap |1| defines a chamber |14 above the diaphragm |18 which is vented to metered Water pressure by a passage |15.

A metering valve is indicated at |16; it contro the area of a metering orifice |11 through which water flows from chamber |54 to chamber |55. The valve |16 has a stem which projects through a guide member, forming part of a bushing |18 which closes off chamber |55 from a bellows chamber |19 in which is mounted a pressure responsive spring loaded bellows |88. One end of the bellows |88 is anchored by means of a threaded stem |9| to a cap or cover |82, while the opposite or movable end thereof is provided with a cup-shaped member having an abutting connection with the stem of the valve |16, a light spring |88 encircling the valve stem and normally urging the said stem against said member. A passage |84 communicates interstage duct pressure to the bellows chamber |19, which pressure for engines having certain characteristics has proven satisfactory as la reference pressure for the water metering valve |16. However, this reference pressure may be taken from the intake manifold direct or from any other suitable point, as desired and found advisable for the particular engine to which thewater metering system may be applied.

A check valve |85 prevents backfiow of fuel into the water metering system from chamber |56; the pressure at which it will open being predetermined by adjustable spring |86.'

A derichment valve control valve is indicated at |98; it controls a port |9| through which inlet water pressure may be communicated by way of passage |92, chamber |98 and conduit |94 to the chamber 14 of the valve 66 (compare Figure 3 with Figures i and 2). The valve l| 98 is connected to-a diaphragm |95 which forms a, movable wall between the chamber |98 and a chamber |96, the latter being in communication with the unmetered water chamber |54 by way' of passage |91. A spring |98 is located in the chamber- |96 and normally urges the valve |9| toward seated position; it predetermines the differential' pressure acting on the diaphragm |95, at which the Y valve |9| will open, and it closes the valve when the differential drops below a certain value. y A vent passage |99 communicates chamber-.|54 as well as chamber |96 with a line 288 leading back tothe water tank, not shown, to insure closing of the derichment control valve under certain conditions and to also vent the system of air before thewater reaches the metering valve. A restriction or bleed 28| communicates conduit |94 with the line 2 88 to insure proper functioning of the valve 66.

It is generally desirable to have an arrangement whereby the manifold pressure will be automatically increased when water is injected, and automatically returned to normal should the system fail or run dry, or when the lwater supply pressure drops below a predetermined value. The particular or specific means by which this may be accomplished forms no part of the pre'sent invention. For. nexample, a pressure switch, Figure l, may be used, said switch comprisinga cylinder 285 having mounted therein a piston 286 which carries a bar 281 of conducting material provided with contacts 288 and 289 adapted to engage companion contacts 2|8 and 2|| carried by an insulated bar 2|2, the latter being inserted in an electric circuit includingground wires 2|8, 2 I4 for the coil 2|5 0f a solenoid valve 2|6, the coil 2|5 being placed in circuit with the contact |68' by means of wires 2|1 and |62.

A manifold pressure bellows 2|8 is mounted in a chamber 2|9 and forms part of a boost control which operates in general like that illustrated in the Smithy and Mock application Serial No. 533,296, heretofore noted. The manifold pressure bellows constitutes part of a variable datum assembly including a datum rod 228 which is con, nected to the movable end of the bellows 2|8 and is encircled by datum spring 22|, adjust-able by means of a lever 222 engaging a slidable bushing or collar 228. The lever 222 is adapted to be controlled from a pilot's power control member or quadrant, not shown. The arm or lever indicated at 224 may control a servo valve for a servo 'system and coacting mechanism which operates to maintain power for a given datum setting by opening the throttles until engine stage supercharger capacity is attained and thereafter increasing the drive on the auxiliary stage system, not shown; it is movable both in response ,to manual adjustment of the datum spring 22| and in response to movement of the bellows 2|8 due to' manifold pressure, should the pressure in thechamberf2|9 drop, due. for example, to a gain in altitude, the bellows 2|8 will extend itself and thereby open the throttles ||8, ||8', and/or regulate the drive on the supercharging system to maintain such manifold pressure.

The manifold pressure chamber 2|9 is in communication with the intake manifold of the engine by way of con-duit 225 and a branch conduit 225 having a bleed 226 therein, and said chamber may also be placed in communication with a. lower pressure source, such as the intake conduit |89, by way of 'a conduit 221 having a bleed 228 therein, the solenoid valve 2|6 controlling s aid latter conduit. When the solenoid ,valve' 2|8 is open, the pressure in chamber 2|8 is lowered independently of the action of the lever 222, and hence the manifold pressure will be increased due to extension of the bellows 2|8, the manifold pressure resuming its normal value upon closing of the solenoid valve 2|6.

The manifold pressure switch 238 is controlled by 9. bellows 28| mounted in a housing 292, the latter defining a bellows chamber 288 which is ,in pressure communication with the engine in'- take manifold by means of conduits 234 and 225.

A spring 235 mounted in the bellows 23|,`normally urges the switch 230 to closed position. This manifold pressure switch is primarily a safety switch in that it insures against the use o1' an auto-lean fuel-air ratio when the manifold pressure is above a given value. The antidetonant or water metering unit operates as follows:

In lthe position of the parts as shown in the drawings, the switch 83 has been turned to normal or auto-rich position and the water pressure switch |6| to on" position; the electric solenoid valve is de-energized, relieving pressure from the chamber 1| between the upper and lower diaphragms 68 and 10, while the derichment valve control valve |90 is open and water pressure has been communicatedv to the pressure switch 205, thereby raising the manifold pressure, and also to chamber 14 beneath` the lower diaphragm 10, thereby closing the derichment valve 66. Metering of primary fuel now takes place through the main metering orifice 60 only.

' The conduit |51 and` chambers |53, |54, |55- and |56 may be considered a continuous flow passage terminating in the mixture chamber |06. Assuming the pilot ofan airplane equipped with a system such as that herein disclosed desires to go into emergency `power with accompanying' water injection and has turned switch |6| to contact |60', as in Figure l, the water pump starts operating and builds up pressure in the chamber |53 and water iiows across the poppet valve |63 (which is then open due to spring pressure) and into the chamber |54, where it acts on the diaphragm |10 in a direction tending to close the poppet valve. From chamber |54,

the water flows through metering orifice `|'l1 into' chamber |55, and` from the latter chamber pressure is communicated to chamber |14 on 'the' opposite side of the diaphragm |10. Since metered water pressure is substantially equal to discharge nozzle pressure (neglecting the drop across the check valve |85) the valve |63 will maintain the pressure in chamber |54 at a substantially constant value above discharge nozzle pressure as determined by the force of spring |13, and this will produce a substantially constant' drop across the metering valve |16 so that the metering of water will be in proportion to the effective area of the metering orifice |11. The position of the valve.|16 which controls this orice is governed by the bellows |80, which is vented to interstage duct pressure. For an engine of the type shown, interstage duct pressure constitutes a fairly accurate reference pressure for the desired waterto-'fuel ratio.

The diaphragm |95 of the derichment control valve |90 is responsive to the drop or differential across the poppet valve |63, which differential tends to open the derichment' control valveagainst the resistance of the spring -|96. If ad e` q'uate water supply pressure exists but for som'e reason Ano water is flowing across the metering valve to the discharge nozzle, or should the poppet valve become stuck, there will be no poppet valvev` drp (this being assured even though'the poppet valve` |63 should be tightly closed -by the small bleed'l60 in parallel with the poppet valve |63, which will then equalize the pressures in chambers |53 and |54), and since there will then be no differential pressure across the diaphragm |95, the spring |96 will close the valve 400. In case the supply of water should become exhausted and the supply pressure drop, there will be a when the differential diminishing force acting on the derichment control valve diaphragm in a valve opening direction. whereupon the spring |96 will close the valve lil when the supplyl pressure drops to a predetermined value. For example, should the water system run dry with the pump |59 still running, the latter might otherwise build up suillcient air pressure in the device to maintain the derichment control valve open, a hazard which is overcome by the method of derichment valve control herein disclosed.

When the derichment control valve |90 opens, water pressure is communicated to the pressure switch 205, the solenoid valve 2|6 is opened, thereby bleeding pressure from bellows chamber 2|9 and the manifold pressure is increased; and water pressure is also applied by way of conduit |94 to the chamber 14 of the derichment valve sand both of the diaphragms 68 and 10 move upwardly and close the derichment valve 66. Whenever the water supply runs out, or should the switch |6| be opened and the water pump stopped, valve |90 will close and pressure will be relieved from the chamber 14 by way of conduit |94 and vent conduit 200, while at the same time pressure will be relieved in back of the Apressure switch piston 206, the circuit to the solenoid valve 2|6 broken and the latter will close, thereby returning the manifold pressure to its previous value. The carburetor will then meter on a normal or auto-rich fuel-air ratio.

It will be apparent that certain modifications and rearrangements of parts will be obvious to those skilled in the art, and the invention is therefore not limited to the specific structure used for the purpose of illustration, ,but only'by the appended claims.

We claim:

1. In a fuel feeding system for an engine, in combination, a device for supplying a primary fuel to the engine, a derichment valve operatively associated with said device for obtaining a predetermined fuel-air ratio when an antidetonant is to be injected with the primary fuel, an auxiliary charge injection system for metering the aritidetonant, said auxiliary charging system including a flow passage having a metering orifice therein, a regulating valve upstream of said oriflce for maintaining a metering head across said orifice, a derichment valve control valve, and

means for rendering said latter valve responsivel tothe drop across said regulating valve.

.112. In a fuel feeding system for an engine, in

combination, a device for supplying a primary fuel to the engine, a derichment valve operatively l latter valve responsive tothe drop across said.

regulatingA valve, said means including a diaphragm connected to the said control valve and subjected to the diiierential in pressures upstream and downstream of said regulating valve, and a spring adapted to seat said control valve determined value.

3. In `a fuel feeding system for an engine, in-

pressure drops to a pre--I vice for obtaining a predetermined fuel-air ratio when an antidetonant is to be injected with the primary fuel, an auxiliary charge injection system for metering the antidetonant including a flow passage for the antidetonant having a metering orifice therein, a regulating valve upstream of said orifice for maintaining a predetermined metering head across the orifice, a derichment valve control valve, a diaphragm mounting said control valve, a spring normally urging said control valve towards seated position, means subjecting said diaphragm to the drop across the regulating valve, the arrangement being such that when the differential across said diaphragm is at a predetermined value, said spring closes said control valve to thereby close the derichment valve.

4. In a fuel feeding system for an engine, in combination, a carburetor for supplying a primary fuel to the engine, a derichment valve operatively associated with said carburetor for obtaining a predetermined fuel-air ratio when an antidetonant is to be injected with the primary fuel, an auxiliary charge metering system including a flow passage for antidetonant having a metering orifice therein, a regulating valve upstream of said metering orifice, a diaphragm connected to said regulating valve, means for subjecting said diaphragm to the differential in pressure between metered and unmetered antidetonant, means for regulating the area of said metering orifice as a function of an engine con- ,y dition, a derichment valve control valve provided with a diaphragm and a spring normally urging the control valve to seated position, means subjecting said control valve diaphragm to the drop across said regulating valve whereby said spring will close the control valve when the drop is at a given value, and a bleed by-passing said regulating valve to insure reduction of the drop across said latter valve in the event the regulating valve is closed and there is supply pressure upstream of the regulating valve but no substantial amount of antidetonant is being passed by the auxiliary system.

5. In a f uel metering system for an engine, in combination, a device such as a carburetor for metering a primary fuel to the engine, a derichment valve associated with said device for obtaining a given fuel-air ratio when an antidetonant is to be metered along with the primary fuel, an auxiliary charge metering device provided with ya flow passage for antidetonant having a metering orifice therein, a regulating valve upstream of said orifice arranged to maintain a substantially constant metering head across said orifice, a metering valve for varying the area of said orifice, means responsive to an engine condition controlling said metering valve, means such as a supply pump for delivering antidetonant under pressure to said regulating valve, a derichment valve control valve provided with a diaphragm subjected to the drop across said regulating valve, a spring normally urging said control valve to seated position, the arrangement being such that when the drop across the regulating valve is at a given value the spring will close the control valve, and a bleed or restricted fiow'passage by-passing the regulating valve to insure reduction of the drop across the regulating valve in the event the latter should be closed while the pump is running and maintaining l0 pressure upstream of the regulating valve but no substantial amount of antidetonant is being passed by the auxiliary system.

6. In a fuel metering system for an engine' having an intake manifold, in combination. a carburetor for metering a primary fuel to the engine," a fuel spray nozzle for injecting metered :fuel when the pressure of the fuel attains a predetermined value, an auxiliary charge metering device for supplying an antidetonant to the nozzle with the primary fuel, said auxiliary charge metering device being provided with a flow passage terminating at said nozzle and having a metering orifice therein, a regulating valve upstream of said orifice, a spring normally urging said regulating valve toward open position, a diaphragm connected to the regulating valve and subjected to the differential between unmetered and metered antidetonant and wherebyv the head across said metering orifice is maintained at a substantially constant value above nozzle discharge pressure as determined by said spring, a metering valve arranged to vary the area of the metering orifice, a bellows connected to said metering valve for positioning the latter, and means rendering said bellows responsive to changes in pressure varying with changes in manifold pressure.

7. In a fuel metering system for an engine, in combination, a carburetor for metering a primary fuel to the engine, a fuel spray nozzle for injecting metered fuel when the pressure of the fuel attains a 'predetermined value, an auxiliarycharge metering device forsupplying an antidetonant to the nozzle with the primary fuel, a mixing chamber upstream of the nozzle, said auxiliary charge metering device having a flow passage terminating in said mixing chamber and provided with a metering orifice, a regulating valve upstream of said orifice, a spring normally urging said regulating valve toward open position, a diaphragm connected to the regulating valve and subjected to the differential between unmetered antidetonant and whereby the head across said metering orifice is maintained at a substantially constant value above nozzle discharge pressure as determined by said spring, a derichment valve control valve provided with a spring normally urging it to seated position and a diaphragm subjected to the drop across said regulating valve so that the control valve will open at' a given value of the drop, a metering valve for varying the area of said metering orifice, means for automatically positioning said metering valve as a function of an engine condition, and a check valve downstream of said metering valve to prevent backfiow from said -mixing chamber when the metering pressure of the antidetonant is below the nozzle delivery pressure.

' JAY A. BOLT.

ROBERT W. MOORE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS smith Nov. 25, i947 Certificate of Correction Patent No. 2,447,793. August 24, 1948.

JAY A. BOLT ET AL.

It is herehy ce'ted that er1-0r appears in the printed specflcaton of the abovez* numbered patent requiring correction as fellows:

Column 10, line 44, claim 7, after the Werd unmetered insert and metered;

and that the said Letters Patent should be read With this cofreeton therein that the same may conform to the record of the ease in the Patent Oee.

Signed and sealed this 4th day of January, A. D. 1949.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

